Question

How does the boiling point of a liquid evolve if a non-volatile solute is added?

Answer 1

Hint: A substance's boiling point is the temperature at which the vapour pressure of a liquid equals the pressure around the liquid and the liquid transforms into a vapour. The boiling point of a liquid is affected by the surrounding atmospheric pressure. The boiling point of a liquid in a partial vacuum is lower than the boiling point of the same liquid at atmospheric pressure. The boiling point of a liquid at high pressure is greater than the boiling point of the same liquid at atmospheric pressure.

Complete Step By Step Answer:
The pressure exerted by a vapour in thermodynamic equilibrium with its condensed phases (solid or liquid) at a particular temperature in a closed system is known as vapour pressure or equilibrium vapour pressure. The evaporation rate of a liquid is determined by the equilibrium vapour pressure. It has to do with particles' proclivity for escaping from liquids (or a solid). Volatile refers to a material that has a high vapour pressure at room temperature. Vapor pressure is the pressure exerted by vapour existing above a liquid surface. When the temperature of a liquid rises, so does the kinetic energy of its molecules.
The usual boiling point of any liquid is raised by lowering the vapour pressure (for example, by dissolving a non-volatile solute). The boiling point of a liquid is the temperature and pressure at which the liquid's vapour pressure equals the ambient pressure and vapour bubbles form directly in the liquid. When the ambient pressure is 1 atmosphere, the usual boiling point is stated. Water's typical boiling point is $ 100{}^\circ C $ , ethanol is $ 78.5{}^\circ C $ , and hexane's is $ 68.5{}^\circ C $ .
When a non-volatile substance like sodium chloride is dissolved in water, the vapour pressure is reduced. This may be thought of as dissolved ions partially obstructing and slowing the evaporation of water molecules while keeping the rate of condensation constant. Because of the decrease in vapour pressure, the water (or any solvent) must be heated to a higher temperature in order for the vapour pressure to return to 1 atmosphere. As a result, the boiling point (temperature) rises.

Note:
Bubble formation at a deeper depth in the liquid necessitates a higher temperature due to the increased fluid pressure, which rises above atmospheric pressure as depth rises. The greater temperature necessary to start bubble production is more relevant at shallow depths. The bubble wall's surface tension causes an overpressure in the extremely tiny, first bubbles.